Positional coverage of the radiation belts in (L, B/B₀) coordinates for various missions: Here the radiation belts are represented by the electron fluxes with E > 1 MeV (background picture generated with the SPENVIS tool³). The red dashed outline shows the location of the proton belt for E > 10 MeV. The inset gives information on the type of orbit and the orbital period for each satellite. Within 3 orbits, PROBA-3 covers a large area of the radiation belts (only orbits 1 and 3 are shown).